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Bogging, Squealing And Dying......


Best Answer Willowfest , 06 July 2018 - 09:08 AM

Hi all,

I know it's been a while since this thread was started, but i thought I'd let you know what the cause was.

 

It was discovered by Dean's Minis at Soham. Top bloke!

 

It was a collapsed catalytic converter, which had extensively blocked the exhaust. The back pressure was blowing out of the exhaust manifold gasket, and the down pipe to Cat gasket.

The head gasket was also blowing, but I'm not sure if that was related or coincidence.

 

Dean had a good used inlet manifold,  so it was put back to its original configuration and the temp sensor returned to it's proper place. 

Thermostat housing was also replaced.

 

Anyway, we replaced a few other things whilst it was in there like Lambdas Sensor, Temperature sensor, Thermostat, Rotor Arm and Distributor cap, manifold gasket, studs, nuts, head gasket etc etc.

 

He runs a treat now, and we're enjoying the sunshine driving around with a new lease of life :-)

 

Many thanks to Dean, a man who lives and breathes classic mini's.

 

 

Cheers all

 

Trev

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#1 Willowfest

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Posted 08 April 2018 - 08:56 PM

Hi everyone.

I’m having a nightmare with Foxy, my 1996 Equinox SPi 1300 Mini.

 

It’s a bit of a saga I’m afraid, but I’m hoping someone can help me…

 

We originally had a small coolant leak, which turned out to rotten pipes on the inlet manifold. The mechanic I usually use bypassed the pipes and relocated the temperature sensor into the thermostat housing. We realised it would run richer for longer, until the thermostat opened, but rightly or wrongly figured it wouldn’t be a major problem.

 

I don’t know if it’s related, but that’s when the trouble started, and has deteriorated spectacularly since.

 

The first symptom was that when it got warm, it became reluctant to rev. Any more than about ¼ throttle, and it would bog down, physically slowing down. At ¼ throttle, it would eventually reach say 60mph, reasonably smoothly. There was also a faint whistle coming from somewhere, a bit like a squealing belt, but very faint.

 

A friend volunteered to help, and we read some of these forums and decided to check vacuum pipes first.

Hey presto, the manifold to ECU pipe had been badly routed, and had melted on the exhaust manifold!

We repaired it using some tubing we had handy and tried again. Absolutely no difference

All that happened was the tick over died after about 40 seconds.

 

We checked the Lambdas sensor output, which was running around .950v switching to around .450v and occasionally .175v. but overall running rich. The sensor appears to be reasonably new.

We discovered that all the other vacuum pipes were in bad shape, so I replaced them all with new ones from Mini Spares along with a new Air Filter.

Absolutely no difference

 

We checked the distributor and rotor arm, all looked great, no arcing, good contacts etc.

We replaced the coil, in case it was breaking down under load… no difference

 

The “whistle” was getting louder…. We cannot pinpoint where it’s originating, but we were convinced it was an intake whistle through a crack/gasket etc. It isn’t there at tick over, but as the revs increase it appears, and dies a second or two after the engine returns to idle.

Best way I can describe it is something like a small bearing running dry and howling at high pitch.

 

Next was to remove and inspect the inlet manifold for cracks etc. Nothing found, all gaskets in good order etc etc. Put it all back together again. Again…. no difference

 

By now, the car has become undriveable. IF I can get any revs above tick over, there’s no power to move the car without just dying.

It generally fires up first time, and ticks over ok, but nothing more.

 

We checked the fuel pump was delivering fuel, and bypassed the fuel filter, even though it looks brand new because it comes up on theses forums often as a cause.

Absolutely no difference

 

By now, the “whistle” is really loud and in your face, but still can’t decide where it’s originating. Sometimes it sounds like its behind the engine, sometimes round the front, other times on the right of the engine bay, then on the left …. Grrrrr!!

 

I replaced the fuel in the tank with fresh petrol….surprise surprise…. no difference

I now can’t get it to start at all. It turns over ok, but just catches and dies.

 

Someone has suggested a dislodged baffle in the exhaust, blocking it, causing back pressure, the whistle, the rich mixture readings etc.

Trouble is, I can’t get the bugger to start now so I cant test it!!!

 

If anybody has read this far and has any ideas, they would be gratefully received as we’ve run out!

 

Thanks in advance

 

Willowfest

 

 

 

 

 

 

 

 



#2 Willowfest

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Posted 11 April 2018 - 09:29 PM

Hi again, has anybody got any advice on this issue please?



#3 Ethel

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Posted 11 April 2018 - 11:02 PM

I'm not much good on injection Minis but, could the ECU have tripped into limp home mode and need resetting? Mems also learns and adjusts itself, so suddenly fixing a fault could make it run worse.

 

Air leaks should be worse at idle (if they're connected engine side of the throttle) as there's more manifold vacuum. If you're looking for a whiny bearing, how about the fuel pump - that's a top of my head suggestion, so don't rush out and buy a new pump on the strength of it alone. The pump should run at a fairly constant speed for one thing. Water pump or alternator would make better candidates but not explain the poor running so much.



#4 MacGyver

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Posted 14 April 2018 - 01:05 PM

Exhaust off, try to turn on, switch off as it will be very noisy.
-
Check clutch is still attached...
-
Get head off and check cylinder bores for scratches, my moped did that kind of noise when the engine had seized/forced to unveiled so it still ran for about a year with a squeeking screeching sound. (140kph moped, not standard 😉) the result when I opened it was not pretty...
-
Manifold leaks?

Not much to go on, but I hope it helps.
Don't give up!

Ben

#5 Willowfest

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Posted 06 July 2018 - 09:08 AM   Best Answer

Hi all,

I know it's been a while since this thread was started, but i thought I'd let you know what the cause was.

 

It was discovered by Dean's Minis at Soham. Top bloke!

 

It was a collapsed catalytic converter, which had extensively blocked the exhaust. The back pressure was blowing out of the exhaust manifold gasket, and the down pipe to Cat gasket.

The head gasket was also blowing, but I'm not sure if that was related or coincidence.

 

Dean had a good used inlet manifold,  so it was put back to its original configuration and the temp sensor returned to it's proper place. 

Thermostat housing was also replaced.

 

Anyway, we replaced a few other things whilst it was in there like Lambdas Sensor, Temperature sensor, Thermostat, Rotor Arm and Distributor cap, manifold gasket, studs, nuts, head gasket etc etc.

 

He runs a treat now, and we're enjoying the sunshine driving around with a new lease of life :-)

 

Many thanks to Dean, a man who lives and breathes classic mini's.

 

 

Cheers all

 

Trev


Edited by Willowfest, 06 July 2018 - 09:14 AM.





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